Aluminum Heads vs R/T Heads

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72DMag

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Looking at possibly buying the Eddy aluminum magnum cylinder heads. I currently have the big valve R/t heads. They aren't ported they are just smoothed in the runners and have been bowl blended. The cam has about 250 duration for both exhaust and intake and I am around a 545 lift. I'm curious how much more hp I could gain with the aluminum heads??

The R/T heads are very heavy so I know I'll save the weight but other than that I'm wondering if its worth the purchase compared to the heads that I already have. Thanks!
 
Less horsepower with aluminum heads unless you bump up the compression. Thats the idea with aluminum heads along with hardened seats although they will flow more than stock heads.
 
ch1ll said:
Less horsepower with aluminum heads unless you bump up the compression. Thats the idea with aluminum heads along with hardened seats although they will flow more than stock heads.
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I've always heard this and never seen any proof to back it up. I have however watched an engine test with the exact same engine, just swapped iron for aluminum heads of very similar specifications and the aluminum head made more power.
 
ch1ll said:
Less horsepower with aluminum heads unless you bump up the compression. Thats the idea with aluminum heads along with hardened seats although they will flow more than stock heads.
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Completely false... 100% false... an old wives tale....
Complete bullshit.
Tested & proven over and over again.


@72DMag
Saving weight, in this case, approximately 50 lbs. Translates into at best, 1/2 a tenth. And only in a well sorted out set up that is consistent.

Now how much better is one head Han another is mostly found in the differences in the heads flow rates as well as port volumes and cross sectional area.

What are these values between the heads?
 
Yeah I agree I don't think the compression statement is true. But in my case that won't matter and I should have added that with an .035 headgasket and icon pistons I am at 11.2:1 compression right now with the R/T heads. The aluminum heads have a slightly small chamber and if I did the math right it puts me a little bit over 11.4:1.

@rumblefish360

The R/T heads:
60cc chamber
180cc rect. intake runner
2.02/1.625 valves

The eddy alumn heads:
58cc chamber
176cc rect intake runner
2.02/1.60 valves


If my lift is only at the .545 range I wonder if I will see any gain in hp. I was looking to make the car slightly faster (Gain 2 tenths of a second in the 1/8th) with the aluminum heads but I'm not sure if I will see any gain with the eddy heads other than the gain due to the weight as you mentioned.
 
Have you had the R/T heads on a flow bench?
 
I believe the RT Magnum head to be one of the very best production small block heads ever made by Mopar and with a little work a 202 intake and minor porting they will run real close to a as cast Edelbrock or pro Comp style head.
 
K.O. SWINGER said:
I believe the RT Magnum head to be one of the very best production small block heads ever made by Mopar and with a little work a 202 intake and minor porting they will run real close to a as cast Edelbrock or pro Comp style head.
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Was the R/T a production head? If it's the one I'm thinking about, it was the head on the 380hp Magnum crate engine. The R/T truck heads were no different than any other Magnum production head.
 
Okay I am la man but I have read quite a bit about the Magnums and I believe the RT head to be the same head that was on The late model 360 RT,pickups durangos etc now the crate motor 360 may have a 202 valve in them already. Wait to hear from the Magnum crowd.
 
K.O. SWINGER said:
Okay I am la man but I have read quite a bit about the Magnums and I believe the RT head to be the same head that was on The late model 360 RT,pickups durangos etc now the crate motor 360 may have a 202 valve in them already. Wait to hear from the Magnum crowd.
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Now there is a difference between the R/T Dakota/Durango heads and the Mopar R/T heads. The true R/T heads came with 2.02 valves. I believe the OP has these heads, not standard Magnum heads.
 
Hi Yes just to clarify I have the true R/T heads. They are stamped this on the heads themselves. The R/t vehicles sold did not have these heads they were aftermarket via mopar only.
 
K.O. SWINGER said:
Okay I am la man but I have read quite a bit about the Magnums and I believe the RT head to be the same head that was on The late model 360 RT,pickups durangos etc now the crate motor 360 may have a 202 valve in them already. Wait to hear from the Magnum crowd.
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The “Magnum R/T” head is a aftermarket MoPar Performance head.
All other Magnum engines have regular heads no matter what vehicle they came in or what trim level they were badges with. That means any Chrysler production vehicle that was designated a “R/T” DID NOT COME WITH R/T heads, ever!

72DMag said:
Hi Yes just to clarify I have the true R/T heads. They are stamped this on the heads themselves. The R/t vehicles sold did not have these heads they were aftermarket via mopar only.
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Bingo, Bulls Eye, 100% correct-O-mundo!!!!!!!
The MoPar R/T head was ONLY AVAILABLE through MoPar Performance.
 
rumblefish360 said:
The “Magnum R/T” head is a aftermarket MoPar Performance head.
All other Magnum engines have regular heads no matter what vehicle they came in or what trim level they were badges with. That means any Chrysler production vehicle that was designated a “R/T” DID NOT COME WITH R/T heads, ever!



Bingo, Bulls Eye, 100% correct-O-mundo!!!!!!!
The MoPar R/T head was ONLY AVAILABLE through MoPar Performance.
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No wonder the flow numbers were so good LOL my mistake thanks guys
 
I also want to add that theR/T heads you have should be flow tested to see where they are for sure to make the best decision possible. Your work on the heads may not be close to what Steve D has on his heads, better or worse, it should be know .

A well ported RT head should out flow the Edelbrock head.
A fully ported RT head should be about the same as a fully ported Edelbrock head.
The Edelbrock head flows about as well as a good ported LA head. Hence the reason there so super popular when first released and still today.
The LA head ported can exceed a OOTB Edelbrock head.
I have not seen a ported LA flow 300 cfm (or real close to it) like an Edelbrock head can be.
 
K.O. SWINGER said:
No wonder the flow numbers were so good LOL my mistake thanks guys
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The OOTB R/T head was very good as cast. They flowed about as well as a average bowl ported head, a few cfm better than a good 330 as cast head. Minor work like a basic bowl blending really helps the head perform well in street bound vehicles. These were only semi popular at best, when they were released.
 
if your running 11.2/1 with iron heads, you should be able to run one point higher with aluminum heads. then yes more horse power, but that takes new pistons.
 
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Don’t believe everything you read... even more so from Hughes.
 
Why, what makes you think you know what I don't?
 
Ok not looking for arguing here. My question has been answered. For the cost of the aluminum heads its not worth buying them given the heads I already have and the little if any hp I will gain. Move along and thanks for all comments everyone!
 
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